[Gluster-devel] md-cache improvements

[Vijay Bellur]

On 08/16/2016 07:22 PM, Michael Adam wrote:
> Hi all,
>
> On 2016-08-15 at 22:39 -0400, Vijay Bellur wrote:
>> Hi Poornima, Dan -
>>
>> Let us have a hangout/bluejeans session this week to discuss the planned
>> md-cache improvements, proposed timelines and sort out open questions if
>> any.
>
> Because the initial mail creates the impression that this is
> a topic that people are merely discussing, let me point out
> that it has actually moved way beyond that stage already:
>
> Poornima has been working hard on these cache improvements
> since late 2015 at least. (And desperately looking for review
> and support since at least springtime..) See all her patches
> that have now finally already gone into master recently
> (e.g. http://review.gluster.org/#/c/12951/ for an old one
> that has just been merged)
> and all the patches that she has still up for review
> (e.g. http://review.gluster.org/#/c/15002/ for a big one).

I perhaps could have provided more context in my email. I have followed 
some of this work closely and it is in line with how I would like to see 
md-cache evolve. My intention behind scheduling this meeting is to:

a> Get a better understanding of the current state of affairs

b> Determine what workload profiles can benefit from this improvement

c> Facilitate reviews and address pending open issues, if any, for 3.9 
and beyond.

>
> These changes were mainly motivated by samba-workloads,
> since the chatty, md-heavy smb protocol is suffering most
> notably from the lack of proper caching of this metadata.
> The good news is that it recently started getting more
> attention and we are seeing very, very promising performance
> test results!
> Full functional and regression testings are also underway.

Good to know! Look forward to understand more about the nature of 
performance improvements in the call or over here :). I think metadata 
intensive workloads from fuse/gfapi can also benefit from this 
improvement. We can hopefully start doing more focussed tests to 
validate this hypothesis post the call.

>
>> Would 11:00 UTC on Wednesday work for everyone in the To: list?
>
> Not on the To: list myself, but would work for me.. :-)
> Although I have to admit it may really be very short notice for
> some...
>

I agree that this is a very short notice. 3.9 being 6 weeks away is 
driving the urgency largely.

> And since Poornima drove the project thus far, and was mainly
> supported by Rajesh J and R.Talur from the gluster side for long
> stretches of time, afaict, I think these three should be present
> bare minimum.
>

Thank you for letting me know whom I missed. Rajesh, R. Talur - look 
forward to see you folks in the meeting!

Regards,
Vijay